mbed application to pair with Evothings App, demonstrates how to create a custom GAP advertising packet.

Dependencies:   BLE_API mbed nRF51822

Intro

This code is meant to demonstrate how to use the GAP advertising layer to transmit data. Keep in mind you only have 26B of data in the Manufacturer data field to use.

Details

Fill in the data you want to transmit by changing the following line

/**
  You have up to 26 bytes of advertising data to use.
  Make up your own encoding for these 26bytes, send it across
  and decode it using the evothings app.
 */
const static uint8_t AdvData[] = {"ChangeThisData"};             // example of character data
//const static uint8_t AdvData[] = {0x01,0x02,0x03,0x04,0x05};   // example of hex data

Name Device

Optionally you can give your device a name by uncommenting the following two lines

//const static char     DEVICE_NAME[]        = "ChangeMe!!"; // change this
...
//ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));

Viewing Data

You can use either the LightBlue app on iOS or the nRF Master Control Panel application on Android to view the advertising data. Alternatively you can use a custom Evothings App to view the data.

Add Disconnection Callback

This code is bare bones and as such does not restart advertising when disconnected from a device. To add this functionality into your code please add the following callback

// Restart advertising when phone app disconnects
void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
{
    ble.startAdvertising(); 
}

and the following initialization to your main function

int 
main(void)
{
...
ble.onDisconnection(disconnectionCallback);
...

Evothings?

Evothings is a rapid prototyping environment that uses cordova to enable you to rapidly develop smartphone applications in Javascript. Please download the Evothings workbench to your computer and the Evothings client to your smartphone. Then grab the code from the github page, drag and drop the index.htm file into Evothings workbench and run it on the Evothings client.

Reference

Committer:
mbedAustin
Date:
Thu Apr 02 20:26:52 2015 +0000
Revision:
12:4b3c795a48d4
Parent:
11:c9c0c4586c5f
hotfix for changed API

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedAustin 1:0692bee84264 1
mbedAustin 1:0692bee84264 2 // Headers necessary for mbed and BLE device mode
mbedAustin 0:5375be4301ed 3 #include "mbed.h"
mbedAustin 0:5375be4301ed 4 #include "BLEDevice.h"
mbedAustin 0:5375be4301ed 5
mbedAustin 1:0692bee84264 6 // BLE object
mbedAustin 1:0692bee84264 7 BLEDevice ble;
mbedAustin 0:5375be4301ed 8
mbedAustin 11:c9c0c4586c5f 9 // Optional: Device Name, add for human read-ability
mbedAustin 8:5442739198ec 10 //const static char DEVICE_NAME[] = "ChangeMe!!"; // Optional: device name
mbedAustin 5:fff16d283dcf 11
mbedAustin 11:c9c0c4586c5f 12 // You have up to 26 bytes of advertising data to use.
mbedAustin 11:c9c0c4586c5f 13
mbedAustin 8:5442739198ec 14 //const static uint8_t AdvData[] = {"ChangeThisData"}; // example of character data
mbedAustin 7:f9a2fa5b1d43 15 const static uint8_t AdvData[] = {0x01,0x02,0x03,0x04,0x05}; // example of hex data
mbedAustin 1:0692bee84264 16
mbedAustin 11:c9c0c4586c5f 17 // Optional: Restart advertising when phone app disconnects
mbedAustin 8:5442739198ec 18 void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason){
mbedAustin 8:5442739198ec 19 ble.startAdvertising();
mbedAustin 8:5442739198ec 20 }
mbedAustin 8:5442739198ec 21
mbedAustin 1:0692bee84264 22 // main program
mbedAustin 1:0692bee84264 23 int main(void)
mbedAustin 0:5375be4301ed 24 {
mbedAustin 1:0692bee84264 25 // Initialize BLE baselayer, always do this first!
mbedAustin 1:0692bee84264 26 ble.init();
mbedAustin 11:c9c0c4586c5f 27
mbedAustin 11:c9c0c4586c5f 28 // Optional: add callback for disconnection
mbedAustin 11:c9c0c4586c5f 29 // ble.onDisconnection(disconnectionCallback);
mbedAustin 1:0692bee84264 30
mbedAustin 1:0692bee84264 31 // Sacrifice 3B of 31B to Advertising Flags
mbedAustin 1:0692bee84264 32 ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE );
mbedAustin 4:d602b1c3aef4 33 ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
mbedAustin 1:0692bee84264 34
mbedAustin 1:0692bee84264 35 // Sacrifice 2B of 31B to AdvType overhead, rest goes to AdvData array you define
mbedAustin 1:0692bee84264 36 ble.accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, AdvData, sizeof(AdvData));
mbedAustin 5:fff16d283dcf 37
mbedAustin 8:5442739198ec 38 // Optional: Add name to device
mbedAustin 5:fff16d283dcf 39 //ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
mbedAustin 1:0692bee84264 40
mbedAustin 1:0692bee84264 41 // Set advertising interval. Longer interval = longer battery life
mbedAustin 12:4b3c795a48d4 42 ble.setAdvertisingInterval(100); // 100ms, set as percentage of a second
mbedAustin 1:0692bee84264 43 ble.startAdvertising();
mbedAustin 1:0692bee84264 44
mbedAustin 1:0692bee84264 45 // Infinite loop waiting for BLE events
mbedAustin 1:0692bee84264 46 for (;;) {
mbedAustin 8:5442739198ec 47 ble.waitForEvent(); // this saves battery while waiting for callback events
mbedAustin 1:0692bee84264 48 }
mbedAustin 1:0692bee84264 49 }